Understanding Phone Configuration Files | Cisco Systems ATA187I1ARF

Chapter 2 Preparing to Install the ATA 187 on Your Network

Understanding Phone Configuration Files

Configuration files for a phone are stored on the TFTP server and define parameters for connecting to Cisco Unified Communications Manager. In general, any time you make a change in Cisco

Unified Communications Manager that requires the phone to be reset, a change is automatically made to the phone’s configuration file. If the system needs to reset or restart, both ports must reset or restart at the same time.

Configuration files also contain information about which image load the phone should be running. If this image load differs from the one that is currently loaded on a phone, the phone contacts the TFTP server to request the required load files. (These files are digitally signed to ensure the authenticity of the file source.)

In addition, if the device security mode in the configuration file is set to Authenticated and the CTL file on the phone has a valid certificate for Cisco Unified Communications Manager, the phone establishes a TLS connection to Cisco Unified Communications Manager. Otherwise, the phone establishes a TCP connection. For SIP phones, a TLS connection requires that the transport protocol in the phone configuration file be set to TLS, which corresponds to the transport type in the SIP Security Profile in Cisco Unified Communications Manager.

Note If the device security mode in the configuration file is set to Authenticated or Encrypted, but the phone has not received a CTL file, the phone tries four times to obtain it so it can register securely.

Note Cisco Extension Mobility Cross Cluster is an exception, in that the phone permits a TLS connection to Cisco Unified Communications Manager for secure signaling even without the CTL file.

If you configure security-related settings in Cisco Unified Communications Manager Administration, the phone configuration file will contain sensitive information. To ensure the privacy of a configuration file, you must configure it for encryption. For detailed information, see Configuring Encrypted Phone Configuration Files in Cisco Unified Communications Manager Security Guide.

A phone accesses a default configuration file named XmlDefault.cnf.xml only when the phone has not received a valid Trust List file containing a certificate assigned to the Cisco Unified Communications Manager and TFTP.

If auto registration is not enabled and you did not add the phone to the Cisco Unified Communications Manager database, the phone does not attempt to register with Cisco Unified Communications Manager. The phone continually displays the “Configuring IP” message until you either enable auto-registration or add the phone to the Cisco Unified Communications Manager database.

If the phone has registered before, the phone accesses the configuration file named

ATA<mac_address>.cnf.xml, where mac_address is the MAC address of the phone.

For SIP phones, the TFTP server generates these SIP configuration files:

•SIP IP Phone:

–For unsigned and unencrypted files—ATA<mac>.cnf.xml

–For signed files—ATA<mac>.cnf.xml.sgn

–For signed and encrypted files—ATA<mac>.cnf.xml.enc.sgn

•Dial Plan—<dialplan>.xml

–No support “,” for second dial tone; “,” will be ignored

Cisco ATA 187 Analog Telephone Adaptor Administration Guide for SIP (Version 1.0)

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